1. Field of the Invention
The present invention is directed toward an air and liquid flow control that regulates the flow of air and a liquid dessert product into the freezing chamber of a frozen dessert dispensing machine. More particularly, the claimed invention allows a user to control the volume of liquid flow into the freezing chamber of the dispensing machine, allowing the machine to operate more efficiently and produce a higher quality product.
2. Prior Art Statement
"Soft" ice cream dispensing machines were developed shortly after the introduction of electrically powered refrigeration. Such machines can be used to make and dispense such soft confectionery products as aerated ice cream, custard, milk shakes, frozen yogurt, or other similar partially frozen dessert products. Most all machines designed to dispense soft confectionery products operate in the same manner. Positioned above a freezing chamber is a reservoir that contains the desired dessert product in liquid form. Air and the liquid product are then selectively introduced into the freezing chamber where they are whipped until frozen, the result being an aerated frozen product, or what is commonly called a "soft" frozen dessert.
The freezing chamber can only freeze a small amount of liquid material in a given time. Consequently, the amount of liquid product introduced into the freezing chamber must be regulated, in view of the capacity of the machine and the rate by which frozen product is finally dispensed. For example, during a hot summer day a frozen dessert machine may be constantly in use, so the flow of liquid product into the freezing chamber would be at a maximum. Conversely, on a cold winter day, the frozen dessert machine may not be used at all and the flow of new liquid product into the freezing chamber would be stopped.
When too much liquid is permitted to enter the freezing chamber, the dispensing machine must run for a long period of time to freeze the product. Since the freezing chamber is overfull, the resultant product may not be properly mixed with air. The lack of proper aeration may result in a product that may be grainy in texture, lack proper taste, and not stand up properly on a cone or in a cup. The machine must then be emptied and reprimed with a new mix of product.
In many frozen confectionery dispensing machines, the device that regulates the amount of liquid and air that enters the freezing chamber are combined into one piece, commonly called an "air tube". The air tube is hollow and extends from the freezing chamber, through the liquid product reservoir, and into the open air. The air tube also has an orifice in its circumferential skin that allows liquid product from the reservoir to enter. As gravity makes the liquid product flow through the orifice, into the air tube, and into the freezing chamber, air is also drawn from above the reservoir. Many variations on the design of the air tube exist in prior art, showing that the regulation of flow of air and liquid into a freezing chamber is a long-standing concern. The prior art that shows inventions that control the flow through such air tubes are as follows:
In the Owner's Manual for the Taylor Freezemaster 750 Series, frozen confectionery dispensing machine, on pages 17 and 21, the air tube design is shown and described. The air tube used has one orifice on its circumferential surface near one end. The air tube is reversible. When the orifice end of the air tube is placed in the bottom of the liquid product reservoir, the liquid flows into the freeze chamber at one uncontrolled rate. When the air tube is inverted, no liquid can flow into the freeze chamber. This system is both inefficient and unsanitary. With the air tube so positioned, so that liquid flows into the freeze chamber, the freeze chamber, if not in constant use, quickly fills with liquid. To stop the flow of liquid into the freeze chamber, a user must put his/her hand into the liquid product, grab the air tube, remove it, invert it and replace it into position. This procedure contaminates the liquid product, which is eventually consumed. During off-peak seasons, the air tube may have to be inverted almost once an hour, causing sever contamination to the liquid product and requiring the user to expend a great deal of time and effort. Additionally, as the air tube is being removed and inverted, the flow of liquid into the freeze chamber is unchecked, flooding the freeze chamber until the air tube is replaced. The excess product must then be removed and discarded from the freeze chamber, resulting in waste and inefficiency.
U.S. Pat. Nos. 4,045,976 to Mills; 4,329,853 to Mills; and 4,850,250 to Mills all show air tubes with various configurations and baffles that permit the smooth flow of both liquid and air through the air tube. None of the aforementioned Mills patents provide a device to selectively and variably control the flow of the liquid into the air tube.
U.S. Pat. No. 4,831,839 to Anderson et al shows as valve arrangement that prevents the overflow of liquid product into the freeze chamber. This arrangement is not variable and has very limited versatility.
U.S. Pat. No. 4,412,428 to Giannella shows a valve system operated through cam action by the rotation of the mixing mechanism. This system is complex, expensive, requires maintenance, is not easily retrofitted into existing machines, and requires parts to wear while in the presence of a consumed food product.
U.S. Pat. Nos. 3,898,858 to Erickson and 4,617,802 to Fiedler show air tube valves that are varied by floats in the liquid product. This requires that a large volume of liquid product be stored on the machine, which may result in the spoilage of the product (which is usually dairy) and waste.
Thus, although prior art does exist that shows a plurality of mechanisms and configurations for controlling the air/liquid flow in a frozen confectionery dispensing machine, prior art neither teaches nor suggests the air tube control device claimed herein that provides an efficient and sanitary flow control that is both variable and easily retrofitted onto existing dispensing equipment.